Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 8e8b7c2b28c54386…

MALICIOUS

RTF / .DOC

67.2 KB First seen: 2023-10-20
MD5: b0b86bfd22a6b86afacf910c0ddd2038 SHA-1: a84d11c8c7bca462d5f39ed19a66515fe95506b1 SHA-256: 8e8b7c2b28c543865c2ed1daf83251385ee097e9a9bfcbf32df9b195a95e7888
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The sample is an RTF document containing an embedded OLE object, specifically leveraging the Equation Editor vulnerability. The document body contains a lure explaining why users might need to enable editing, a common tactic to bypass security measures. The presence of \objupdate indicates an attempt to automatically activate the embedded object, likely to trigger the exploit.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00002ab5.bin
ebdb4d8df406c5e11e7c6afa3f90c7da60ace40a5cad79d502f2f02e737aa770
rtf-objdata-decoded RTF \objdata at offset 0x2AB5 1745 bytes